1. Field of the Invention
The present invention relates to a recording material determination device for detecting a surface texture by capturing an image of a surface of the recording material and detecting a basis weight by an ultrasonic wave transmitted through the recording material to determine a kind of the recording material, and an image forming apparatus including the recording material determination device.
2. Description of the Related Art
In the conventional image forming apparatus, image forming conditions such as a fixing temperature and a conveyance speed of the recording material are controlled according to a kind of a recording material and an image is formed with a stable image quality independent from the kind of the recording material. Therefore, an example of the recording material determination device to determine the kind of the recording material includes a device to expose the recording material to light and determine a surface texture of the recording material, for example, based on the reflected light reflected on the recording material. Another example includes a device to expose the recording material to an ultrasonic wave and determine the basis weight of the recording material based on the ultrasonic wave transmitted through the recording material.
Japanese Patent Laid-open Publication No. 2009-29622 discusses a method for improving a determination accuracy of the recording material by a combined use of an optical-system recording material determination device and an ultrasonic wave-system recording material determination device. In Japanese Patent Laid-open Publication No. 2009-29622, in a case where the optical-system and the ultrasonic wave-system recording material determination device are combined for the use, detection processing of the respective recording material determination devices are concurrently performed where a roller is provided to pinch the recording material to avoid an interference between the ultrasonic wave-system and the optical-system recording material determination device so that no degradation of the detection accuracy of the recording material may occur. The degradation of the detection accuracy occurs when the recording material is vibrated when the detection is performed by the ultrasonic wave-system recording material determination device. Accordingly, a time taken in the detection of the recording material can be shortened.
However, although the roller enables a suppression of the interference, there is such a problem that it is hard to achieve a downsizing and cost-saving of the recording material determination device since additional members are required in order to suppress the interference between the two systems.